## Wednesday, October 5, 2011

### Modeling Unit 6

Unit VI: 2-D Particle Model

Our introductory/paradigm demo was Jon and Chris tossing a ball back and forth.  Jon then asked questions like: "Once it leaves my hand, where will it go?""Does the ball have a choice as to where it goes after it leaves my hand?"

One thing that come to mind during this demo was the following video from Veritasium.com:

What do you notice?
What can you measure?
{at this point, Jon showed us the equipment that we would be using}
{Jon build hold that converts dynamic cart w/ spring into ball launcher}
Here's a rough sketch:

Where the blue shape is the dynamics cart with the spring plunger extended, the silver circle is the ball to be launched, and the brown shape is the holder Jon built out of wood.  He also cut/routed a groove for the ball to roll in on the top of the "shelf."
After being shown equipment What can you manipulate?

{If you don't have time to build this and have students tape it, use videos in loggerpro}
Open logger pro
Click Insert - Movie
Click “expand menu” in bottom right corner
Click scale icon (looks like a ruler)
Make sure you have scale (meter stick) in the movie
Click and trace standard length in screen & define length
Click on track (find name) button and click on specific point on object
Continue clicking on the same spot of the object (vernier advances to next frame)

Jon and Chris then tried to show us the classic Monkey-Blow gun demo using the Pasco equipment:

Since this is quite expensive, Jon explained how he made a "homemade version" of this:
Materials:
Electric conduit (1/2 inch? Metal)
Nail with cone of paper hot glued in
Electromagnet
Wire
12 V power source (3 or 6 V should also work)
Target - Balloon with brass mass inside, washer stretching the opening
Stuffed animal with metal screw in its head

He attaches the Electromagnet to the ceiling in the back of his room and runs the ingoing and outgoing wires above is ceiling (drop-down I'm guessing) to the front of his room.  He uses the conduit as the blow gun and makes darts by gluing cones of paper to the head of the nail.  Have the two wires run up the side of the conduit and each extent the bare wires beyond the opening of the conduit.  Bend the wires so they touch in the middle of the opening.  As the dart shoots out, it will separate the wires, breaking the connection. Here's his sketch:
(click to embiggen)

I missed this day of the workshop, however, a few of my cohort were gracious enough to take notes.  I'm doing my best to take what they gave me.  Any help to clarify things would be greatly appreciated.

The day began with everyone working on Unit VI worksheet.  Everyone worked individually, and then the groups met to create whiteboards.

- Useful to separate horizontal and vertical givens in table:

-Good to explicitly show + state that t is the same for horizontal and vertical motion
-Good to keep algebra in variable until the last step - then plug in number

#4 Would be interesting in adding a horizontal & vertical motion map for car and ball

-stress constant velocity in horizontal direction

- ESL students have difficulty with "how long" thinking it means distance

- After students have generated data, insert 3 graphs + auto arrange
• x vs t
• y vs t
• \$v_x\$ vs t
• \$v_y\$ vs t
-Highlight first 1.5 second to analyze
•  compare slope of x vs t and average value of \$v_x\$ from \$v_x\$ vs t graph
• lead students to see that \$v_x\$ is constant by \$v_y\$ is changing (slope is 9.8 \$m/s^2\$)
• If you want, have students insert a quadratic fit onto y vs t graph and lead them to find what the meaning of the constants are in the regressed equation.
Next on the agenda was to split up an article to have summarized on whiteboards by the groups.

After lunch, Jon and Chris asked for feedback for Unit VI
What worked:
Video analysis lab
Plan for Dart Gun for Classic Monkey Problem
Worksheet #3
Hammer article about Lisa & Ellen
Group Work
Adaptability of labs to every level of student (*response to comment on what didn't work)

What didn't work:
Transition from 1D to 2D - we would like to see the process
Time constraints
Simplicity of labs*